1. Field of the Invention
This invention relates generally to a pain treatment device, and more particularly to transcutaneous electrical nerve stimulation (TENS) devices and methods for programming and operating such devices to maximize effectiveness.
2. Description of the Prior Art
Chronic pain plagues over 100 million Americans on a daily basis. Many health regimens have been developed to alleviate chronic pain involving a variety of evidence-based and nonevidence-based therapies. Pain treatment programs usually involve pharmacological agents or neurosurgical/anesthesia based interventions. Unfortunately, some of the most effective treatments have serious side effects, lose their potency with prolonged use, result in dependence or are prescribed in inadequate amounts. Because of this, the search for pain treatment programs has involved a variety of adjuvant treatments including transcutaneous electrical nerve stimulation (TENS) and acupoint stimulation (acupuncture).
Although there were efforts to utilize electrical stimulation to suppress pain 2000 years ago, a detailed, scientific investigation was finally conducted by Professor Galvani of the University of Bologna in the early 1800s. In 1967, Dr. Sweet developed one of the first modem electrical apparatus for suppression of organic pain. TENS (transcutaneous electrical nerve stimulation) is a procedure that applies controlled bursts of electrical impulse on the skin to the nervous system in order to reduce pain. A mild tingling sensation and possibly muscle twitch is felt by the patient using a TENS device. A TENS device can be used by a patient at varying locations numerous times throughout the day. TENS therapy is based on a non-invasive, non-narcotic concept of pain management. It is non-addictive, not subject to abuse and does not interact with drugs. TENS has been proven to be an effective modality in the treatment of a variety of organic pain problems including: chronic neck and back pain, bursitis, arthritic disease.
Although there are many theories as to transmission of pain from the nervous system to the brain, gate control and endorphin theory have emerged as the best and most generally accepted evidence based explanations for the efficacy of TENS in the treatment of pain. Melzack and Wall in 1965 described the Gate Control Theory of Pain (GCT). (Melzack, 1965) GCT states that pain can be inhibited and controlled by xe2x80x9cclosing the gatexe2x80x9d on pain signals as they arrive at the central nervous system. Pain impulses traveling along a nerve, through the spinal cord, and to the brain can be modified at any point along the transmission route. Pain signals carried by small, slow conducting peripheral nerve fibers (C-fibers) can be blocked by many things including stimulation of the large diameter, rapidly conducting peripheral nerve fibers (A fibers). GCT occurs in a segment of the spinal cord containing many T-cells called the Substantia Gelatinosa. The balance between A and C fibers determines the degree of pain. Stimulation of A fibers by a variety of stimuli (scratching, pressure, vibration or high amplitude electrical stimulation) without much stimulation of C fibers, will close the gate. Unfortunately, the problem of accommodation requires more and more variation of treatment parameters to keep the gate closed to pain.
The major problem with electrical stimulation, however, continues to be accommodation, whereby the stimulated nerve accommodates itself over time to the electrical charge, diminishing the effectiveness of treatment. A variety of U.S. Pat. Nos. (e.g. 2,622,601, 2,771,554) involve TENS devices with the means to vary the rate, amplitude or pulse width of the generated electrical pulse. Unfortunately, accommodation would still occur unless an individual manually adjusted the controls prior to or during the treatment. The process was mentally and physically demanding and maximum pain relief was not provided. For example, U.S. Pat. No. 4,019,519 (Geerling) discloses a unit having only its amplitude adjustable. U.S. Pat. No. 4,084,595 (Miller), and U.S. Pat. No. 4,759,368 (Spanton) disclose TENS devices in which the stimulus signal has a manually and independently varied rate, amplitude and pulse width. To provide improved output pulse compensation, one TENS device (U.S. Pat. No. 5,184,617 to Harris et al.) provides manual adjustment of pulse width control linked to a predetermined change in range of intensity of the pulses. Although variation enabled one to deal with accommodation, pain relief was sacrificed due to the interaction between amplitude and pulse width. As the duration of pulse is shortened, amplitude must be increased to maintain the efficacy of stimulus. The relationship when plotted graphically is known as a strength-duration curve. Thus, not only must a TENS unit have adjustable amplitude and pulse width, but it must also be able to modulate those values to optimize pain relief.
In addition to amplitude and pulse width, the rate of pulses must vary so as to minimize accommodation. U.S. Pat. No. 2,808,826 (Reiner), disclosed a unit that permitted instantaneous changes in pulse width and amplitude to two pre-set points along the strength duration curve. U.S. Pat. Nos. 4,340,063, 4,431,002 and 4,442,839 (Maurer), disclose units with modulation of amplitude, pulse width, and repetition rates, but the problem of accommodation still existed.
Acupuncture has existed in China for over 4,000 years, and it spread to Korea in 300 AD, to Japan in the 1600s and to Europe by the 1800s. Although mentioned in a surgical treatise by Billroth in 1863, and in Osler""s 1912 Principles and Practices of Medicine, interest in the U.S. dramatically increased following Nixon""s 1971 trip to China. The World Health Organization has indicated that over one third of the world""s population is using acupuncture at the present time.
The discovery in 1975 that the pain receptors in the brain are blocked by a variety of endogenous opiate-like substances, including endorphins, was a major advance in the understanding of acupuncture. (Hughes 1975) Endorphin theory postulates that stimulation of the nervous system, by needles or more effectively by low frequency electrical current, will trigger the release of naturally occurring pain making morphine-like substances including endorphins and enkephalins. These naturally occurring substances block pain signals from reaching the brain by a mechanism similar to conventional drug therapy but without the side effects of morphine. Additional factors in the transmission and central amplification of pain signals involve the so-called NMDA receptor and the chemical neurotransmitter substance P. These substances can trigger long-term anatomical changes in both sensory and spinal nerves, making these cells more responsive to later pain stimulation. Endorphin theory and gate control theory have provided a generally accepted neurochemical explanation for the efficacy of acupuncture. (Han 1998)
The importance of proper acupuncture point location has been emphasized for over 3000 years. The traditional 360 physiologically active points were discovered by trial and error. Meridian theory and a variety of pre-scientific era explanations contributed to an increase to over 1000 points. Most of the useful points coincide with motor points and lie close to nerve trunks or Golgi tendon organs. Traditional and electrical acupuncture today may be practiced with knowledge of 50 physiologically active points. (Ulett, 1992)
The use of electrical stimulation of acupoints can be traced back to 1764 in Japan. It is generally accepted that general acupuncture with electrical stimulation increases the effectiveness of pain relief. Evidence based research about acupuncture and acupoint transcutaneous electrical nerve stimulation, however, continues to emphasize the critical importance of finding the proper location and parameters of stimulation for each individual. A circuit for electrotherapy and electronic acupuncture alternated a negative pulse train with a repetition rate of 100 and 500 Hz in groups with a repetition rate of 1 and 50 Hz with a positive bias provided for an integral of pulse train signals of zero is described in U.S. Pat. No. 4,556,064 (Pomeranz et al.). The signal was randomly switched sequentially from one skin stimulus site to another with application times that could be adjusted. Specific microcurrent waveform signals have also been patented in U.S. Pat. No. 5,935,156 (Chandler et al.). A specific acupoint stimulation device for a branch of the vagal nerve located in the ear is disclosed for substance withdrawal, pain relief, stress relief and or general muscle relaxation in U.S. Pat. No. 5,458,625 (Kendall).
Parameters for electrical stimulation are fortunately easier to apply and have been generally more effective than manual needling and manipulation. Locating and optimizing these 50 acupoints, however, continues to be difficult for health providers and is further complicated by the efficacy of multiple site stimulation.
There have been a number of previous patents relating to the measurement, transmission and analysis of health data with provision of therapeutic recommendations. A previous attempt at monitoring a patient""s blood pressure and heart rate, sending the data via telephone to a remote central computer for storage and analysis with reports submitted to the physician or patient is described in U.S. Pat. No. 4,712,562 (Ohayon et al.). A similar system, with the receiving office unit automatically communicating with the physician under predetermined emergency circumstances is described in U.S. Pat. No. 4,531,527 (Reinhold et al.). A device for a patient to use electronics to measure multiple parameters is described in U.S. Pat. No. 4,838,275 (Lee). These data are electronically transmitted to a central surveillance and control office where a highly trained observer interacts with the patient. The observer conducts routine diagnostic sessions, except when an emergency is noted. Similarly, a portable self-contained apparatus for measuring, storing and transmitting detected physiological information to a remote location over a communication system is described in U.S. Pat. No. 5,012,411 (Policastro et al.). An apparatus for alerting a doctor, which provides an alarm corresponding to a patient and receives living body information signals transmitted through a transmitter, is described in U.S. Pat. No. 5,003,984 (Muraki et al.).
One electrotherapy device, such as a pacemaker, cardioverter or defibrillator, contains software code or instructions for operation stored in an attached memory device is described in U.S. Pat. No. 5,836,993 (Cole), but does not involve Internet or CNA. The programming and transmission of treatment parameters to a receiver of an implanted arrhythmia treatment device is described in U.S. Pat. No. 5,607,460 (Kroll et al.). An electronic pain rating scale which can alternatively include a dock and intensity sensor for recording a treatment session duration and intensity is described in U.S. Pat. Nos. 5,653,739 and 5,873,900 (Maurer et al.).
An interactive intervention transmission system used for monitoring a patient suffering from neurological movement disorders or seeking to improve skills performance and to assist in training is described in U.S. Pat. No. 5,810,747 (Brudny et al.). The patient station and supervision station can communicate with each other over the Internet or LAN. An expert system, fuzzy logic or a neural network is used to determine the goal to be achieved during the training. No modification of parameters involving a pain reduction or medical device is involved. A remotely programmable patient operated hand-held apparatus uses a communication network such as the world wide web to allow the health care provider to obtain patient data and to develop a script program is described in U.S. Pat. Nos. 5,822,715 (Worthington et al.) and 5,960,403 (Brown). The hand-help apparatus also obtains patient information supplied by a physiologic monitoring device, such as a blood glucose monitor in U.S. Pat. No. 6,168,563 (Brown).
A system and method for providing computerized, knowledge-based medical diagnostic and treatment advice using a network such as the Internet is found in U.S. Pat. Nos. 5,935,060 and 6,022,315 (Lliff). A system and method for communicating with an ambulatory delivery device, preferably a drug pump, both locally and remotely is described in U.S. Pat. No. 6,024,539 (Blomquist). A computer system comprising a control program for an intravenous device for infusion therapy based on input entered by the user is described in U.S. Pat. No. 6,012,034 (Hamparian et al.). The input and output interface will be in electrical communication with the computer device, but will not directly modify the parameter settings. A method and system for managing mechanical ventilator of patients uses data, processed according to a set of protocols and medical decision-making rules, to generate detailed executable instructions for patient care in U.S. Pat. No. 6,148,814 (Clemmer et al.). Patient care instructions can be carried out automatically or manually.
These patented devices, however, do not address situations where a portable piece of medical equipment is remotely programmed responsive to patient input criteria, and also do not involve the combination of Internet, CNA, and a patient or remote computer input/output interface. This is especially desired in the pain management field where self-administering patients often do not have the necessary background to properly program their portable TENS devices to address specific symptoms. Accordingly, a need remains for a system and method for addressing these deficiencies.
The present invention provides a method involving the use of Internet or combinations of network architectures to manage and treat chronic pain involving coordination between a patient, health providers, central computer with knowledge based program, remote computer with input/output interface and pain reducing device with input/output interface. The method includes a central computer with knowledge-based program to receive, store and analyze patient specific information. The patient or health provider will enter information into a remote computer terminal including: medical diagnoses, pain characteristics (including severity, characteristics, duration), patient functional status and patient psychosocial profile. Previous experience with evidence and non-evidence based treatment modalities will also be entered including: pharmacological pain treatment (pills or other drug-type forms), medical pain treatment, whether the treatment was non invasive or invasive (e.g. nerve blocks), physical and massage therapy, experience with pain reduction devices (e.g. transcutaneous electrical nerve stimulation (TENS)), chiropractic manipulation, traditional Chinese Medicine and homeopathy. The central computer with knowledge-based program can also be expanded to include other evidence based and non-evidence based treatment modalities.
The method includes a computer knowledge based program to receive, store and analyze patient specific information. The program helps a remote and/or central health provider to evaluate the effectiveness of pain treatment and makes specific patient recommendations regarding pain management and utilization and settings for a pain reduction medical device.
The information will be locally stored and transmitted from the entry terminal via Internet or combinations of network architectures to the knowledge base where data will be received stored and analyzed. An optional security layer will also be provided to prevent unauthorized access to the central computer. The security layer will comprise any standard security scheme or technology and may be used system wide as well as with all workstations, Internet applications, patients, and health providers. The central and/or remote medical provider, who can select to communicate to the remote health provider, patient or pain reduction device, will then review all knowledge based program recommendations. Patient data and pain reducing device data will be available for analysis on the three levels: manual, semiautomatic and automatic.
In the manual mode of operation, the knowledge-based program will primarily summarize data and perform minimal analysis. After reviewing the relevant pain data, the central health provider issues instructions to the patient and/or remote health provider via either textual commands on the PC monitor, voice and or video images or combinations of these facilities. Recommendations will be made regarding the particular location of optimal acupoint placement, as well as other treatment parameters including for example exercise, massage, or pharmaceutical therapy.
In semiautomatic mode, automated modification and analysis of patient responses will be added to the resources provided by the manual mode. The software knowledge based program will imitate the subjective methods for data analysis using heuristic means by using fuzzy logic.
Fuzzy logic is a branch of technology that solves problems, which include lexical uncertainty. Humans use words as subjective categories to classify parameters such as neck or back pain. While a concept may not be precisely defined, humans use them for complex evaluations and decisions that are used on many different factors. They do so by combining the rules that describe similar situations taking advantage of the flexibility in the definition of the words that constitute the rules. To implement these processes in engineering solutions, by a computer, requires a mathematical model. Fuzzy logic provides such a mathematical model and allows representation of human decisions and evaluation processes in algorithmic form. Although there are limits to what fuzzy logic can do, it can derive solutions for a given set of rules that have been defined for similar cases. If you can describe the desired performance of a technical system for certain distinct cases by rules, fuzzy logic will apply this knowledge to produce a solution. The optimal location of desired acupoints and nerve stimulation parameters is an excellent example of a problem that lends itself to resolution by fuzzy logic.
In the automatic mode, in addition to review of patient and pain reducing device data from the semi-automatic mode, treatment parameters will be recommend by using software based on an expert system. The expert system fixes the type of response to be attempted as well as the goals or parametric values to be achieved. The expert system used in this invention is a computer program that implements adductive reasoning or logic. This seeks to imitate the ways in which human beings draw logical conclusion in practice, even though the conclusions may be flawed. Thus, if one knows that a given predicate p implies that the predicate q and that q is true at the time it is sampled, we conclude that p must also be true. The result that p is now true can lead to additional adductive results and ultimately to some terminal results, which in this case is a recommendation regarding acupoint location and pain management. In the automatic mode, all treatment parameters are recommended by the software module. The medical professional will supervise and be able to intervene when the system is in semiautomatic or automatic modes.
Specific treatment recommendations will be provided including: location of optimal acupoints to treat a given chronic pain, treatment session parameters including number of treatments per day, and recommended duration. When the pain-reducing device is a transcutaneous electrical nerve stimulation (TENS) device, settings will be modified including: frequency, duration, polarity, and waveform. The preferred waveform parameters include: constant current output despite skin conductance changes, identical positive and negative square waves alternating with each other and having a net output of 0, automatic adjustment of pulse width with increase during low frequency stimulation and increase during high frequency stimulation, automatic adjustment of polarity, fixed and variable time intervals of 3 to 5 seconds of 2 to 4 Hz alternating with fixed and variable time intervals of 3 to 5 seconds of 80 to 100 Hz (with and without symmetrical increase and decrease in wave form).
In the preferred embodiment some of the information is transmitted directly to the pain-reducing medical device via the remote computer with. input/output interface regarding pain reduction medical device treatment parameters such as waveform, frequency, duration or polarity. It will also be possible to transmit this information to the patient or health professional in order to adjust the settings of the pain reduction device. Information may also be collected and stored in the pain reduction device and directly transmitted from the remote computer with input/output interface to the physically distant central computer with knowledge base regarding parameters amenable to patient control in the pain reduction device including: treatment duration, characteristics of the electrical pulse, and patient-selected current intensity. The system can be employed to monitor progress and or control the pain management protocols of one or more patients in a concurrent manner.
The central computer with knowledge-based program and central health provider will receive data and transmit instructions to and from the patient, remote health provider, computer with input/output interface and pain-reduction medical device with input/output interface. Data will be transmitted via the Internet or multiple types of combinations of networks architectures including: local area network, wide area network, and television network (transmitted, broadband or cable, public switched telephone network or integrated services digital network). The information will be formatted with output to a communication device involving various combinations of video and voice. Video conferencing interface involving a camera and microphone located at the knowledge base as well as patient station is also included.
Information regarding the epidemiology of chronic pain, therapeutic interventions and efficacy can also be recorded, stored and analyzed by the knowledge-based program. The effectiveness of different pain treatment protocols for example involving location, frequency of use, duration, and polarity and other treatment parameters will also be statistically analyzed to optimize recommendations.
By having a knowledge base help to generate recommendations as to treatment points, health providers as well as the patient will be able to locate effective acupoints for stimulation. Although location is important, it will not be beyond the abilities of most patients to place TENS electrodes at recommended acupoints because of the spread of current through the local tissues. Settings for the pain reduction device involving parameters including waveform, frequency, duration and polarity are also important. The pain manager program can recommend settings to the provider or at times directly to the patient. In the preferred embodiment, although not necessary or appropriate for all situations, the settings for the pain-reducing device can be directly entered into the pain-reducing medical device via the input/output interface, such as a docking station with the remote computer. If the pain reduction medical device is implanted, there will also be a patient input/output interface in proximity or attached to the patient.
The foregoing and other objects, features and advantages of the invention will become more readily apparent from the following detailed description of a preferred embodiment of the invention that proceeds with reference to the accompanying drawings.